Is Santa Nella, CA tap water safe?
The short answer
1 of the 2 utilities serving Santa Nella has a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and California’s records: City of Gustine.
City of Gustine, which serves the most people here, has 2 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 39 ppb, above EPA’s health benchmark. Health goals are stricter than legal limits and are not enforced.
The water from City of Gustine is very hard, typically 360 mg/L (21.1 grains per gallon). How California’s water compares.
A town can be served by more than one utility, and some homes are on private wells. The name on your water bill tells you which is yours, and your ZIP code narrows it down. They are listed by how many people each serves in Santa Nella’s ZIP codes, from EPA’s estimates.
- Open report
City of Gustine
California · serves 6,138 people · about 170 in Santa Nella
2 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 39 ppb, above EPA’s health benchmark. Hardness: very hard, typically 360 mg/L (21.1 grains per gallon).
1 health-based violation since 2016
- Open report
Santa Nella County Water District
California · serves 2,211 people · under 100 in Santa Nella
2 results above the health goal. The worst: Arsenic at 4.4 ppb, above the health goal. Hardness: moderately hard to very hard depending on the source, 103 to 250 mg/L (6 to 14.6 grains per gallon).
No health-based violations since 2016
What handles it
Each of these is certified, on a certifier’s listing, for a result above a line in City of Gustine’s water, which serves the most people here. Another utility’s report names what handles its own results.
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Countertop reverse osmosis
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 4, 2026
Certified for: Arsenic
Aquasana SmartFlow Reverse Osmosis (AQ-SFRO2)
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Arsenic
Brondell Capella RC250 Reverse Osmosis System
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Arsenic
Water testing near Santa Nella
The 3 labs California certifies closest to Santa Nella, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Certified Laboratories - Turlock
Turlock, CA · about 23 miles
Certified for bacteria
Microbac Laboratories, Inc. - Turlock
Turlock, CA · about 24 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, radioactivity
CM Analytical, Inc.
Gilroy, CA · about 31 miles
Certified for bacteria
ZIP codes in Santa Nella
Which ZIP codes are in Santa Nella: Census 2020 relationship files. Which utilities serve them, and how many people: EPA SDWIS and EPA’s service area map. Each utility’s results: EPA UCMR 5, EPA SDWIS, and EPA’s and the state’s compliance monitoring, as its report lists them. How they are measured: methodology. Certified labs: California State Water Resources Control Board, ELAP accredited laboratories and their fields of accreditation; distances from the Census 2020 ZIP code tabulation area gazetteer.
Near Santa Nella
Other towns in Merced County with a page of their own.
What to do next
- Read City of Gustine’s full reportEvery result with its dates, the violations, and the certification claim that handles each finding.Open the report
- About LithiumWhat it does to health, where it comes from, and the certification claim that addresses it.About Lithium
- On a private well?No utility tests a well. A certified lab test is the first step.How to test well water